Create a Minecraft (Spigot/Paper) plugin that adds a coin flip betting game using a GUI. When a player runs /coinflip, open an inventory GUI with two options: Heads and Tails, shown using distinct items. After the player selects an option, prompt them to enter a bet amount via chat or a secondary GUI, validating minimum/maximum limits and balance. Once confirmed, start an animated coin flip in the GUI by switching items in a central slot, along with sound effects. After a few seconds, randomly choose Heads or Tails. If the player guessed correctly, reward them with double their bet; otherwise, deduct the bet. Integrate Vault for economy support. Add cooldowns and prevent multiple games at once. Include a config file for bet limits, animation duration, sounds, messages, and cooldown. Structure code into command, GUI, game manager, economy, and config classes.